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PREDICTION OF LOADING DISTRIBUTION AND HYDRODYNAMIC MEASUREMENTS FOR PROPELLER BLADES IN A RIM DRIVEN THRU-STER

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Journal of Hydrodynamics 2012年第1期24卷 50-57页

作者： cao Qing-ming HONG Fang-wen TANG Deng-hai HU Fang-lin LU Lin-zhang China Ship Scientific Research Centre Wuxi 214082China

This article presents an approach which employs a commercial Reynolds-Averaged Navier-Stokes（RANS）solver to predict the steady wake field and loading distributions for a rim driven *** different cases of propeller blades are chosen to be calculated with the presented *** propeller blade radial circulation and chordwise circulation density distributions are *** maximum radial circulation is found at the blade tip,which is different from conventional shaft driven *** numerical results indicate that there is no tip leakage vortex in rim driven *** there exist the tip joint vortex and the root region *** characteristics are calculated by taking rim surface effect into *** the predicted results the second case in this paper is selected as the final one to perform hydrodynamic *** calculation results with empirical rim surface corrections are compared with the *** shows that the developed numerical method can well predict hydrodynamic performances of the rim driven thruster.

关键词： rim driven thruster Reynolds-Averaged Navier-Stokes(RANS)solver wake field radial circulation chordwise circulation density hydrodynamic experiment

Flower Opening Simulation Based on Key Lines Using WebGL

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Wuhan University Journal of Natural Sciences 2015年第3期20卷 235-239页

作者： JIN Ping ZHENG Wen cao ming LIU Jinshuo School of Urban Design Wuhan University China Ship Development and Design Center School of Computer Wuhan University

A flower opening simulation based on key lines model is proposed. First, this model generates several petals with b-spline surfaces based on key lines. Second, a flower bud is constructed according to layers of the bud and petal numbers in each layer. Then, flower opening process is simulated with Logistic function. At last, flowers opening simulations of seven types are carried out with Web GL. The results show that, using this model, the average rendering time of these 7 flowers is 195.84 s, the minimum rendering time is only 12.23 s in gardenia flower opening simulation. Compared with Takashi＇s method, this model is more efficient in flower opening simulation process.

关键词： flower modeling flower simulation key lines Logistic

Statistical performance of IF estimation of LFM signals with timevarying amplitude using the peak of WVD

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Journal of Systems Engineering and Electronics 2005年第4期16卷 787-791页

作者： Chen Guanghua Ma Shiwei Qin Tinghao Wang Jian Li ming cao Jialin Microelectronic Research & Development Center Shanghai Univ. Shanghai 200072 P. R. China

The instantaneous frequency （IF） estimation of the linear frequency modulated （LFM） signals with time-varying amplitude using the peak of the Wigner-Ville distribution （WVD） is studied. Theoretical analysis shows that the estimation on LFM signals with time-varying amplitude is unbiased, only if WVD of time-varying amplitude reaches its maximum at frequency zero no matter in which time. The statistical performance in the case of additive white Guassian noise is evaluated and an analytical expression for the variance is provided. The simulations using LFM signals with Gaussian envelope testify that IF can be estimated accurately using the peak of WVD for four models of amplitude variation. Furthermore the statistical result of estimation on the signals with amplitude descending before rising is better than that of the signals with constant amplitude when the amplitude variation rate is moderate.

关键词： instantaneous frequency linear frequency modulated signals Wigner-Ville distribution statistical performance variance.

Investigation on Mechanism of Altitude Characteristic for Air-breathing Pulsed Laser Thruster

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Chinese Journal of Aeronautics 2010年第1期23卷 33-38页

作者： Hong Yanji,Wen ming,cao Zhengrui Department of Basic Theories,Academy of Equipment Command & Technology,Beijing 101416,China Department of Basic Theories Academy of Equipment Command & Technology Beijing 101416 China

Altitude characteristic is of great importance for studying when an air-breathing pulsed laser thruster works in the dense atmosphere condition of 0-30 km altitude. The experimental findings all over the world show that the similar relationship between impulse coupling coefficient and altitude. According to strong explosion theory and an ideal gas model,a dimensionless factor indicating energy law of similitude is introduced,and formula of impulse coupling coefficient is deducted. Then theoretical study of altitude characteristic is carried out and mechanism of altitude characteristic is further explained. The results indicate that there is a maximum value of impulse coupling coefficient if the dimensionless factor equals to 0.41 in theory, and whether the phenomena of maximum appear or not depends on the range of the dimensionless factor related to altitude. As to a conical nozzle with the fixed length of 120 mm, the relationship between the sonic velocity and the dimensionless factor causes the maximum phenomenon at the altitude of about 12.5 km,and maximum theoretical impulse coupling coefficient is also found in the experimental investigations. The mechanism of altitude characteristic for air-breathing pulsed laser thruster is discovered in this article, which will provide reference for further research on altitude characteristic.

关键词： laser propulsion air-breathing mode altitude characteristic dimensionless factor maximum phenomenon

Reduction mechanisms of pyrite cinder-carbon composite pellets

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International Journal of Minerals,Metallurgy and Materials 2012年第11期19卷 986-991页

作者： Zheng-jian Liu Xiang-dong Xing Jian-liang Zhang ming-ming cao Ke-xin Jiao Shan Ren State Key Laboratory of Advanced Metallurgy School of Metallurgical and Ecological EngineeringUniversity of Science and Technology BeijingBeijing 100083China

The non-isothermal reduction mechanisms of pyrite cinder-carbon composite pellets were studied at laboratory scale under argon （Ar） atmosphere. The composite pellets as well as the specimens of separate layers containing pyrite cinder and coal were tested. The degree of reduction was measured by mass loss. The microstmctures of the reduced composite pellets were characterized by scanning electron mi- croscopy （SEM）. It is found that the reduction processes of the composite pellets may be divided into four stages： reduction via CO and H2 from volatiles in coal at 673-973 K, reduction via H2 and C produced by cracking of hydrocarbon at 973-1123 K, direct reduction by carbon via gaseous intermediates at 1123-1323 K, and direct reduction by carbon at above 1323 K. Corresponding to the four stages, the apparent activation energies （E） for the reduction of the composite pellets are 86.26, 78.54, 72.01, and 203.65 ***-1, respectively.

关键词： pyrite ore pellets reduction microstructure activation energy

Differential bonding behaviors of sodium/potassium-ion storage in sawdust waste carbon derivatives

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Chinese Chemical Letters 2024年第4期35卷 496-501页

作者： Jun-ming cao Kai-Yang Zhang Jia-Lin Yang Zhen-Yi Gu Xing-Long Wu MOE Key Laboratory for UV Light-Emitting Materials and Technology Northeast Normal UniversityChangchun 130024China Department of Chemistry Northeast Normal UniversityChangchun 130024China

Sodium-ion batteries(SIBs) and potassium-ion batteries(PIBs) are the most promising alternatives to lithium-ion batteries, and thus have drawn intensive research attention. Porous carbon materials from different precursors have been widely used as anode materials owing to their compatible storage effectiveness of both larger radii sodium and potassium ions. However, the differential bonding behaviors of Na and K ions with porous carbon-based anode are the significant one worth investigating, which could provide a clean picture of alkali ions storage mechanism. Therefore, in this work, we prepare a porous carbon network derived from sawdust(SDC) wastes, to further analyze the differences on sodium and potassium ions storage behaviors in terms of bond-forming process. It is found that, as-prepared SDC anodes could deliver stable sodium and potassium storage capacities, however, there are notable distinctions in terms of electrochemical behaviors and diffusion processes. By virtue of ex-situ XRD and Raman spectroscopy, the phase transition reaction of potassium ions could be well-observed, and the results shows that the multiple intercalated compounds was formed in SDC network during ions insertion, further resulting in slower diffusion kinetics and larger resistance compared to non-bonded process of sodium ions storage. This study provides more insights into the differences between sodium and potassium ions storage, as well as the energy storage mechanism of porous carbon as anodes for secondary batteries.

关键词： Porous carbon Sodium-ion storage Potassium-ion storage Bonding behaviors Batteries

Two-dimensional Nb_(3)Cl_(8)memristor based on desorption and adsorption of O_(2)molecules

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Rare Metals 2022年第1期41卷 325-332页

作者： Jian-Gang Chen Gui-ming cao Qing Liu Peng Meng Zheng Liu Fu-Cai Liu School of Optoelectronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore

As a novel two-dimensional(2D)semiconductor material with biocompatibility and ferromagnetic properties,Nb_(3)Cl_(8)exhibits a great prospect in the field of implantable electrical *** this work,the effects of the light illumination and the gate voltage on the desorption of O_(2)molecules from Nb_(3)Cl_(8)were systemically investigated via the in situ electrical transport characterization in the vacuum *** experimental results showed that the light illumination and the negative gate voltage could enhance the desorption of oxygen molecules while the positive gate voltage could promote the re-adsorption of O_(2).The multi-bit storage function was demonstrated via adjusting the p-doping effect caused by oxygen adsorption.A novel mechanism of optical writing and electrical erasing in this Nb_(3)Cl_(8)memristor was proposed,which was in coincidence with the expected results of the control experiment in *** results shed light on the great potential of Nb_(3)Cl_(8)in high-density data storage,neuromorphic,wearable applications and implantable devices application.

关键词： desorption illumination electrical

Effect of Temperature on Scale Morphology of Fe-1.5Si Alloy

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Journal of Iron and Steel Research International 2013年第11期20卷 73-78页

作者： LIU Xiao-jiang cao Guang-ming HE Yong-quan JIA Tao LIU Zhen-yu State Key Laboratory of Rolling and Automation Northeastern University

Because of the effect of silicon on the formation of oxide scale, red scale is the main surface defect of hot rolled Fe-Si plate, making the scale difficult for descaling compared with carbon steel. Thermogravimetric analyzer （TGA） is used to simulate isothermal oxidation process of Fe-1.5Si alloy for 60 min under air condition, and the temperature range is from 700 to 1 200 ℃. Electron probe microanalysis （EPMA） is used to observe cross-sectional scale morphology and analyze elemental distribution of the scale. Relational graph of temperature, scale thickness and scale structure is obtained. It is found that scale structure （outer Fe oxide layer＋inner FeO/Fe2SiO4 layer＋internal Si oxide precipitates） is almost unchanged with temperature except at 1000 and 1 200 ℃. At 1000 ℃ internal Si ox- ide precipitates cannot be found at the subsurface of the alloy, and at 1200 ℃ FeO/Fe2SiO4 not only forms a layer as usual but also penetrates into the outer Fe oxide layer deeply.

关键词： Fe 1.5Si alloy scale morphology internal oxide precipitate Fe2SiO4

Kinetic Studies on Aniline-catalyzed Carbohydrate Oxime Formation via Real-time NMR

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Chemical Research in Chinese Universities 2011年第5期27卷 886-890页

作者： WANG Wen-jun cao Chen-ming JIN Chen WANG Xin WANG George-peng College of Pharmacy Nankai University Tianjin 300071 P. R. China State Key Laboratory of Element-Organic Chemistry Nankai University Tianjin 300071 P. R. China Departments of Chemistry and Biochemistry The Ohio State University Columbus OH 43210 USA

The authors investigated an aniline-catalyzed method to accelerate the reaction between equimolar reducing glycans and hydroxylamines. The rate-constants determined by real-time NMR were associated with the equivalence ratio of aniline rather than the concentration. Conjugates of oligosaccharide with hydroxylamine can be obtained in high efficiency at pH=5.4.

关键词： Glycoconjugate Aniline Catalysis Kinetics Real-time NMR